The present invention relates to a speaker damper in which a plurality of wave parts are formed in a damper base that is formed by impregnating a fabric material formed by weaving warp and weft in an interlaced manner with a resin, and a speaker unit using the speaker damper.
In related-art speaker dampers, a wavelike shape is adopted in order to give a margin for their vibrating motions. In general, this wavelike shape is formed so that concentric circles are formed in the plan view (i.e., as viewed from the top). A cloth-like material that is formed by weaving warp and weft is used for the damper. Wave parts (or wavy parts) are press-formed so that the damper can expand and contract. A fabric material used as a raw material is impregnated with a resin. The above-described dumber base material is affected by the property of threads that are woven into the warp and the weft and a resin solvent that is used to increase the strength of the fabric material. The strength and the flexibility of the damper in the directions along (i.e., in parallel with) the threads, which intersect each other at right angles, are different from those of the damper in the directions inclined from the threads by 45 degrees. Therefore, when the damper performs expanding/contracting motions, different expanding/contracting motions occur in the above-described different directions. When the magnitude of the expanding/contracting motions of the damper is increased, the damper is more likely to bend (or warp) in the directions in which the flexibility is large. In contrast to this, the damper is less likely to bend (or warp) in the directions in which the flexibility is small. As a result, the damper is distorted. Such distorted motions make smooth vibrating motions performed by the damper difficult.
Therefore, Japanese Unexamined Patent Application Publication No. H9-154199 discloses a technique for solving such a problem. In a speaker damper disclosed in this publication, an amount of collapse of a damper base in directions inclined from threads by 45° is increased when wave parts are press-formed in the damper base. In this way, the rigidity of the speaker damper in the directions inclined from the threads by 45° is improved.